Review Reports

Round 1

Reviewer 1 Report

The paper „The effects of zinc oxide/silicon dioxide composite coating on surface wettability and mechanical properties of paper mulching film” investigates different coatings on papers. Although the paper is interesting, a few ambiguities should be corrected.

• Fig 1. describes the coating process, ZnO is first applied, followed by SiO2, as shown in the upper row. In the lower row, the order is reversed, where ZnO appears as the top layer.
• In the text, there is almost always a dot after Figure
• By comparing micrographs in fig.2, different scales make comparison difficult. How has the average diameter been determined?
• On page 4, last paragraph you should revise the description of the element contents (c element…)
• Generally, you should revise axes designators in your diagrams, e.g. fig.6b x-axis distance per µm? Maybe [µm] would be better. The same applied to other figures, too. BTW, I assume that “fibrpus layer” is a typo?
• I wouldn’t call fig. 7 a diagram
• A decimal place (e.g. CA 131.53°) which indicates a larger accuracy as does the error range doesn’t make sense in my opinion
• In fig. 8b, values indicate CA after a full test cycle of 20 repetitions of bending operations as shown in fig. 7? Maybe you should explain that somewhat more detailed
• In fig. 9 you should indicate what paper is coated and which is uncoated
• Regarding tensile tests, again I have some doubts on the accuracy of 2 decimal places. Have you performed multiple tests and values presented are average values? Again, please check diagrams, like fig 10c – translate/mm?
• How have the temperature distributions in figs. 14 and 15 at the sample surfaces been measured? Have you verified absolute temperature values?

Author Response

Reviewer1:

1. Fig 1. describes the coating process, ZnO is first applied, followed by SiO2, as shown in the upper row. In the lower row, the order is reversed, where ZnO appears as the top layer.

In the text, there is almost always a dot after Figure

By comparing micrographs in fig.2, different scales make comparison difficult. How has the average diameter been determined?

On page 4, last paragraph you should revise the description of the element contents (c element…)

Generally, you should revise axes designators in your diagrams, e.g. fig.6b x-axis distance per µm? Maybe [µm] would be better. The same applied to other figures, too. BTW, I assume that “fibrpus layer” is a typo?

I wouldn’t call fig. 7 a diagram

Response: Thanks for the reviewer’s advice. The coating process described in Figure 1 is that both sides of the paper mulch are first brushed with ZnO, and then brushed with SiO2. Sorry, the errors in the pictures and language descriptions in the article have been revised and marked in the article.

Original: “Fig. 8 is a comparison diagram of contact angles between the original paper mulching film and the coated paper mulching film and a contact angle diagram corresponding to the mechanical bending cycle times of the coated paper mulching film. By observing and analyzing the contact angle data in Fig. 8(b), mechanical bending and mechanical twisting cycle steps (b), (c), (d) and (e) in Fig. 7, a set of contact angle data is measured every 20 times for comparative analysis. With the increase of mechanical bending and mechanical twisting cycles, the contact angle degree of coated paper mulch film decreases, but it still keeps good hydrophobic property.

Modified: “Fig. 8 is the contact angle comparison chart of the original paper mulch film and the coated paper mulch film and the contact angle map corresponding to the number of mechanical bending cycles of the coated paper mulch film. By observing and analyzing the contact angle data in Fig. 8 (b), mechanical bending and mechanical distortion Steps (b), (c), (d) and (e) in Fig. 7 are cycled. Each time the mechanical bending and mechanical twisting interval is 20 times, the sample is taken out to measure a set of contact angle data for comparative analysis. As the number of mechanical bending and mechanical twisting cycles increases, the contact angle of the coated paper mulch decreases, but it still maintains good hydrophobic properties.”

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2. A decimal place (e.g. CA 131.53°) which indicates a larger accuracy as does the error range doesn’t make sense in my opinion

In fig. 8b, values indicate CA after a full test cycle of 20 repetitions of bending operations as shown in fig. 7? Maybe you should explain that somewhat more detailed

In fig. 9 you should indicate what paper is coated and which is uncoated

Regarding tensile tests, again I have some doubts on the accuracy of 2 decimal places. Have you performed multiple tests and values presented are average values? Again, please check diagrams, like fig 10c – translate/mm?

How have the temperature distributions in figs. 14 and 15 at the sample surfaces been measured? Have you verified absolute temperature values?

Response: Thanks for the reviewer’s advice. The temperature of the sample surface in Figure 14 and Figure 15 is the temperature measured during the experiment. The reason for this is to ensure the rigor of the experiment. Sorry, the errors in the article have been revised and marked in the article.

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Reviewer 2 Report

Review of the article: The effects of zinc oxide/silicon dioxide composite coating on surface wettability and mechanical properties of paper mulching film

   The topic of this research and output might be useful for the Coatings readers. The conducted work is worth to publish, however in order to improve the manuscript the following suggestions should be considered. The lines have not been numbered, which makes it difficult to refer to a specific text.

Abstract:

1. Hydrophobicity and durability of original paper mulch film and coated paper mulch film were measured by static contact angle and mechanical torsion tests, and mechanical properties of the two kinds of paper mulch films were measured by tensile and tear tests at different temperatures.

• Please divide this sentence into two.
• … mechanical torsion tests, and mechanical properties….  Why mechanical torsion tests is not a mechanical one, is not in this group?

2. superhydrophobic and hydrophobic durability

• What are the criteria for the division into these two groups?
• Can the material be superhydrophobic and hydrophobic?

Introduction

1. Why is it sometimes written super hydrophobic, sometimes superhydrophobic, super-hydrophobic?
2. What are the differences? Please provide a description, a definition of the term superhydrophobic, so that it can be distinguished from the term hydrophobic?
3. The mechanical properties of paper mulch film will decrease due to climate and other factors in use.- climate or climate conditions?
4. “excellent durability”, “super strong support”- These are not scientific terms. Please specify them.
5. The zinc oxide coating filled and bonded the pores between the fibers of paper mulch film, and the silicon dioxide coating made the paper mulch film obtain superhydrophobic performance by constructing micro-rough structure on the surface of paper mulch film. The hydrophobic property and mechanical property of paper mulch film were improved by this composite coating modification.- This is a form of conclusions. This part should be in the conclusion.

Experimental part

1. Figure 1.- Is there a reference in the text to Figure 1?  

Performance test of samples

1.  A more detailed description of the contact angle tests should be provided, i.e. what liquid was used, what was the droplet volume, what test method... Please look at the description, e.g.  

• Gindl, M.; Sinn, G.; Gindl, W.; Reiterer, A.; Tschegg, S., 2001: A comparison of different methods to calculate the surface free energy of wood using contact angle measurements. Colloids and Surfaces A – Physicochemicaland Engineering Aspects, 181 (1-3): 279-287
• Laskowska A., Kozakiewicz P. 2017: Surface wettability of wood species from tropical and temperate zones by polar and dispersive liquids. Drvna Industrija 68 (4): 299 - 3062.

2. Were the tests conducted according to any standards?

Results and discussion

1. Please standardize the references to Figure. Sometimes there is a record of e.g. Figures. 3 (a) and 3 (d), Figureure…
2. Why there is a dot after the word Figure. This misleads the reader when reading.
3. Please make your literature references in the Results section. It is given in the introduction, and in the Result part, the results of the research/ observations should be confronted with other works.
4. Figure 5. Why does the word paper appear twice in the Figure i.e. “Raw paper paper”?
5. Figure 7. What is the purpose of presenting these images? They should come from a testing machine.
6. Record e.g. 131.53°±1.5- The standard deviation should be given with the same accuracy as the result, i.e. to two decimal places.     

Comments for author File: Comments.pdf

Author Response

Reviewer2:

1. Hydrophobicity and durability of original paper mulch film and coated paper mulch film were measured by static contact angle and mechanical torsion tests, and mechanical properties of the two kinds of paper mulch films were measured by tensile and tear tests at different temperatures.

Response: Thanks for the reviewer’s advice. The experimental process of the mechanical torsion is shown in Figure 7.

Original: “The results show that the contact angle of ZnO/SiO2 composite coated paper mulch film reaches 161.46°, and the contact angle can still reach 153.15° after 80 mechanical torsion cycles, which shows good superhydrophobic and hydrophobic durability.”

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2. Superhydrophobic and hydrophobic durability

What are the criteria for the division into these two groups?

Can the material be superhydrophobic and hydrophobic?

Response: Thanks for the reviewer’s advice. The criteria for evaluating superhydrophobic and superhydrophobic durability are that the contact angle exceeds 150°. The superhydrophobic durability refers to the fact that the surface of the material is still in a superhydrophobic state after repeated mechanical torsion experiments. The original material does not have superhydrophobic, and it has superhydrophobic after our surface treatment.

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3. Why is it sometimes written super hydrophobic, sometimes superhydrophobic, super-hydrophobic?

What are the differences? Please provide a description, a definition of the term superhydrophobic, so that it can be distinguished from the term hydrophobic?

Response: Thanks for the reviewer’s advice. For the definition of superhydrophobic, there are references in the article. In addition, in order to ensure the rigor of the paper, all hydrophobic in the paper are now changed to superhydrophobic. It has been marked in the article.

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4. The mechanical properties of paper mulch film will decrease due to climate and other factors in use.- climate or climate conditions?

“excellent durability”, “super strong support”- These are not scientific terms. Please specify them.

  Response: Thanks for the reviewer’s advice. Sorry for the inaccurate text in the article. The revised sentence has been marked in the article.

Original: “Avijit et al. [18] introduced the preparation of fluoroalkyl functionalized fiber paper base with water as medium, and found that the paper base has excellent durability against mechanical-chemical damage in daily use.”

“ Yu et al. [19] filled "sticky" mineral particles into the fiber network of paper, which made paper-based products have super strong support and strong adhesion to water.”

Modified: “Avijit al. [13] introduced the preparation of fluoroalkyl functionalized fiber paper base in water, and found that the mechanical-chemical damage resistance of the paper base was enhanced and the durability was improved.”

“Yu et al [14] filled "sticky" mineral particles into the fiber network of paper, which improved the support of paper base and strong adhesion to water.”

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5. Figure 1.- Is there a reference in the text to Figure 1?

Response: Thanks for the reviewer’s advice. Sorry, the revised part has now been marked in the article.

Original: “and finally take out the prepared ZnO/SiO2 composite coated paper mulching film.”

Modified: “and finally take out the prepared ZnO/SiO2 composite coated paper mulching film, as shown in Figure 1.”

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6. A more detailed description of the contact angle tests should be provided, i.e. what liquid was used, what was the droplet volume, what test method... Please look at the description, e.g.

Gindl, M.; Sinn, G.; Gindl, W.; Reiterer, A.; Tschegg, S., 2001: A comparison of different methods to calculate the surface free energy of wood using contact angle measurements. Colloids and Surfaces A – Physicochemicaland Engineering Aspects, 181 (1-3): 279-287

Laskowska A., Kozakiewicz P. 2017: Surface wettability of wood species from tropical and temperate zones by polar and dispersive liquids. Drvna Industrija 68 (4): 299 - 3062.

Were the tests conducted according to any standards?

Response: Thanks for the reviewer’s advice. The liquid used in the contact angle test is water, the droplet volume is 4 microliters, and the test standard is that the contact angle is greater than 150°. Sorry, the revised part has now been marked in the article.

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7. Please standardize the references to Figure. Sometimes there is a record of e.g. Figures. 3 (a) and 3 (d), Figureure…

Why there is a dot after the word Figure. This misleads the reader when reading.

Please make your literature references in the Results section. It is given in the introduction, and in the Result part, the results of the research/ observations should be confronted with other works.

Figure 5. Why does the word paper appear twice in the Figure i.e. “Raw paper paper”?

Figure 7. What is the purpose of presenting these images? They should come from a testing machine.

Record e.g. 131.53°±1.5- The standard deviation should be given with the same accuracy as the result, i.e. to two decimal places.     

Response: Thanks for the reviewer’s advice. Sorry, the revised part has now been marked in the article.

Round 2

Reviewer 2 Report

The authors made the necessary corrections. The article needs to be edited to the requirements of the Coatings journal e.g. references.